The present invention relates in general to McPherson-strut suspension units for motor vehicles, of the type comprising a telescopic shock-absorber including a tube carrying a wheel mounting at its lower end, a rod slidable through the upper end of the tube, a helical compression spring surrounding the shock-absorber, and a resilient connection for connecting the free end of the rod to the body.
Suspension units of this type have a problem in that the transverse components of the forces transmitted from the wheel in use tend to cause the shock-absorber, and particularly its rod, to be deformed by bending since its connection to the body is conventionally formed in such a way that the point at which the transverse forces are applied coincides with the region of its free end. The bending of the rod makes it difficult for it to slide and causes it to jam in the tube.
In order to resolve this problem, it has been proposed to connect the rod to the body in an arrangement such that the plane in which the rod bears against the body is displaced below the free end of the rod so as to reduce the lever arm of the transverse loads applied thereto and thus to reduce the bending.
Solutions of this type are described, for example, in FR-A-2301399 and DE-A-2626392. In both cases, the connection for fixing the rod to the body includes a member substantially in the form of an inverted cup fixed at its upper end to the free end of the rod and at its lower end to an annular block of elastomeric material connected to the body. The block is situated at the level of the body and the cup-shaped member, together with the portion of the rod surrounded thereby, therefore extends above the region where the shock-absorber is connected to the body. This projection obviously involves greater transverse bulk of the suspension unit and consequent difficulties in adapting the bodywork of the vehicle to enable its installation.